Fuel cutoff means



April 29, 1941;

A. G. BLANCHARD 2,239,774

FUEL CUTOFF MEANS Filed June 5, 1939 Patented Apr. 29, 1941 UNITEDSTATES vPATENT OFFICE FUEL CUTOFF MEANS Alva G. Blanchard, Shreveport,La.

Application June 5, 1939, Serial No. 277,333

2 Claims.

The invention relates to mechanism for con.- trolling the admission offuel to the combustion chamber of steam generators and more particularlyto a construction which is operable to cut off the admission of fuelwhen the liquid level within the generator exceeds a predeterminedlimit.

It is a general object of the invention to provide in combination with asteam generator means operable by pressure generated therein for cuttingoff the fuel supply when the liquid level changes beyond predeterminedlimits.

It is also an object to provide in such combination a fuel control valvewhich is normally retained in open position but which is movable to aclosed position by virtue of a pressure connection with the generator.

Another object is to provide a fuel control valve which is soconstructed that the fuel pressure will maintain the valve closed whenclosure has taken place by pressure generated within the steamgenerator.

Another object is to provide a fuel control valve which, when closed isheld in closed position by the pressure of the fuel supply and whichmust thereafter be opened manually to admit additional fuel thru thesupply line.

Another object is to provide a fuel control valve having a movable stemwhich is operatively connected to a pressure chamber so that the stemwill be moved to close the valve when there is pressure in the chamber.

These and other objects will be apparent from the following descriptiontaken in connection with the drawing in which:

Fig. 1 is a sectional view of a valve construction comprising an elementof one embodiment of the invention.

Fig. 2 illustrates the invention as comprising a fuel line in which thevalve of Fig. 1 is utilized, such valve and fuel line being operativelyconnected to a steam generator.

Referring further to the drawing, the invention comprises a fuel controlvalve I connected in. the fuel supply line 2 by means of which asuitable fuel is supplied to the boiler or steam generator 3. A conduit4 is attached through a liquid level valve 5 to the pressure chamberwithin the boiler and to a pressure chamber within the valve l to servea purpose that will be more fully apparent by further reference to theconstruction illustrated in Fig. 1. The liquid level valve 5 may be ofany desired type and may be so constructed that actuation thereof takesplace either when the liquid within the generator becomes too high ortoo low.

The fuel control valve, generally designated as l is shown in Fig. 1, ascomprising a valve body It which is connected in the fuel line 2 bymeans of flanges H and I2 which are secured to complementary flanges onsections of pipe comprising the fuel line. This valve body has atransverse wall l3 in which is fitted a valve seat l4 having a seatingsurface l5 at the upper edge thereof. The valve seat I4 lies generallyin a plane extending longitudinally of the body I0 whereby fluid passingtherethru flows in the direction generally indicated by the arrows I6, afeature which enables the functioning of the valve in a manner to bemore fully described.

The side opening 2|] in the valve body Ill is coaxial with the valveseat I4 and is of such diameter as to slidingly receive the valve member2| which is provided with a seating surface l5 on the valve seat l4 sothat engagement of the valve member 2| With the seating surface I5closes the passage thru the valve.

The upper end of the opening 20 is beveled at 25 for engagement with thecomplementary surface on the plug 26 which serves as a closure for theopening and which is secured in place by means of coupling member 21engaging the shoulder 28 on the plug 26 and secured to the body Ill bymeans of threads on the outer surface of the boss surrounding theopening 20.

The plug 26 serves as a closure for the opening 20 and has a centralopening 38 to receive valve stem 3| which is rotatably attached to thevalve member 2| and extends outwardly therethru. In order to preventleakage of fluid along the valve stem 3 I, packing 32 surrounds thevalve stem within the bore 30 and is held tightly in place by means ofthe packing gland 33.

The upper end of the plug 26 is threaded at 40 for connection with aspider 4! which surrounds the valve stem 3|. This spider has atransverse wall having a central opening thru which the valve stem 3!passes. In the wall 45 is a radial opening 46 to receive a latching ball41, a spring 48 and a threaded plug 48 which serve to hold the ball 41in a peripheral groove in the valve stem 3!. By suitable adjustment ofthe threaded plug 49 it is believed apparent that the valve stem isreleasably locked with the valve member 2| in spaced relation with thevalve seat 14 until suflicient pressure is exerted axially of the valvestem to force the ball 4'! outwardly against the force exerted by thespring 48.

The valve stem 3| terminates at its upper end in a head 55 of which theupper surface is closely adjacent a diaphragm 56 clamped upon the upperend of the spider by means of a hollow cap 51 which forms with thediaphragm a pressure chamber 58.

The cap 51 is provided with a threaded boss 60 to which the conduit 4 isattached so that pressure generated within the boiler 3 will be exertedupon the diaphragm 56 within the pressure chamber 58.

The operation of the construction thus far described is believedapparent. Attention is directed to the fact; that the threaded plug 49will be so adjusted that the movable elements of the valve I will bereleasably held against movement under the influence of gravity or otherexternal forces tending to close the valve. If, however, the liquidlevel within the generator fluctuates beyond predetermined limits, theliquid level valve 5 will operate and admit steam pressure to thechamber 58 in the valve I, whereupon the diaphragm 56 will flex and thehead 55 will be moved downwardly together with the valve stem 3| and thevalve member 2| so that the valve will be closed.

It is to be noted that when the seating surface 22 is moved intoengagement with the seating surface l5 upon the seat ring l4 the upperportion 23 of the valve member 2| moves from within the opening 20 andthus permits the incoming fuel to exert a pressure upon the uppersurface of the valve member 2|. The pressure exerted by the fuel is thusinstrumental in maintaining the valve member 2| upon its seat and thevalve will remain closed unless forcibly lifted against this pressure.

In order to provide desirable functioning of the valve, means isprovided for reopening the valve manually, it being intended that thisfeature will cause the operator to know the condition giving rise to thecutting off of the fuel supply so that such condition will be removedbefore the valve is manually opened to resume normal operation of thesystem.

The valve stem 3| is provided with spaced collars 35 and 36 which areattached thereto and which are adapted to be engaged by a lever 31pivotally connected to the spider at 38 and extending outwardlytherefrom thru a slot 39.

When the valve closes, as already described, the lever 31 moves to itslowermost position within the slot 39, and as explained, the valve canthereafter be opened manually by lifting this lever until the lockingball 41 again engages within the recess in the valve stem 3|.

Broadly the invention comprehends a construction including a steamgenerator and a liquid level valve, together with means operable byextremes in fluctuation of liquid level within the generator for cuttingoff the fuel supply thereto, such means being so constructed that manualopening thereof is necessary for the resumption of normal operation.

What is claimed is:

1. A fuel control cutofi valve for steam generators comprising a valvebody, a valve seat therein, an opening in the body coaxial with thevalve seat, a valve assembly including a valve member slidably fittingwithin the opening, a closure for the opening outwardly from the valvemember, a valve/stem attached to the valve member and extendingoutwardly through the closure member, means for releasably locking thevalve stem to hold the valve open, a diaphragm chamber adapted toreceive pressure fluid from the steam generator, a head on said valvestem engageable by the diaphragm of said chamber to move the valve stemfrom engagement by the locking means and move the valve from within saidopening so that the valve assembly moves to close the valve member uponits seat.

2. A fuel cutoff valve for steam generators comprising a valve assemblyincluding a valve having a valve stem extending outwardly therefrom,said valve stem being movable axially to open and close the valve, aspider attached to the valve, a releasable lock between said spider andvalve stem to hold the valve in open position, a presstem, and a leverpivotally attached at one end to the spider and operably connected tothe valve stem for manual return of the valve assembly to open position.ALVA G. BLANCHARD.

